Encapsulation

Customer s care about affordable and reliable access to the utility of asset s. They are not concerned with structural complexity, technical details, or low-level operations. They prefer simple and secure interfaces to complex configurations of resources such as application s, data, facilities, and infrastructure. Encapsulation hides what is not the customer’s concern and exposes as a service what is useful and usable to them. Customer s are concerned only with utilization.

Encapsulation follows three separate but closely related principles: separation of concerns, modularity, and loose coupling.

Separation of concerns

Complex issues or problems can be resolved or separated into distinct parts or concerns. Specialized capabilities and resources address each concern leading to better outcomes overall. This improves focus and allows optimization of systems and processes at a manageable scale and scope. Challenges and opportunities are suited with appropriate knowledge, skills, and experience.

It is necessary to identify persistent and recurring patterns, to separate fixed elements from those that vary, and to distinguish what from how (Figure 2.1). These separations are important for a service-oriented approach to IT management or simply service orientation. For example, it is useful to identify and consolidate demand with common characteristics but different sources and serve it with shared services.

Modularity

Modularity is a structural principle used to manage complexity in a system.12 Functionally similar items are grouped together to form modules that are self-contained and viable. The functionality is available to other systems or modules through interfaces. Modularity contributes to efficiency and economy by reducing duplication, complexity, administrative overheads, and the cost of changes. It has a similar impact through the reuse of modules.

Encapsulation is possible at several levels of granularity, from software and hardware component s to business process es and organizational design. Figure 2.8 illustrates the role of service management in encapsulating business processes and IT applications into business service s and IT service s.

Figure 2.8 Encapsulation based on separation of concerns and modularity

Дата добавления: 2015-11-14